Sheet material transport system



Sept. 9, 1970 E. H. BURNHAM ETAL 3,531,109

SHEET MATERIAL TRANSPORT SYSTEM 3 SheetsSheet 1 Filed May 20, 1968INVENTORS EDWARD H. BURNHAM EDWARD J LAVANDER ATTORNEYS 5 Sheets-Sheet:8

. %%v i N s? 5% 9m Fw Sept. 29, 1970 E. H. BURNHAM ET AL SHEET MATERIALTRANSPORT SYSTEM Filed May 20, 1968 E. H. BURNHAM EFAL 3,531,109

SHEET MATERIAL TRANSPORT SYSTEM 5 Sheets-Sheet 5 Sept. 29, 1970 FiledMay 20, 1968 4 m F a Q 19 9 7 M \k m m l United States Patent Office3,531,109 SHEET MATERIAL TRANSPORT SYSTEM Edward H. Burnham and EdwardJ. Lavander, Rochester, N.Y., assignors to Xerox Corporation, Rochester,

N.Y., a corporation of New York Filed May 20, 1968, Ser. No. 730,465Int. Cl. 1565b 29/28 U.S. Cl. 271-79 4 Claims ABSTRACT OF THE DISCLOSUREA sheet conveying system for carrying sheet material from a deliverystation to a discharge station having a rod rotatably mounted forengagement with spring stock wherein the sheet material is securedbetween the rod and sheet material for positive gripping.

This invention relates to sheet conveyer systems and, in particular, toan improved sheet gripper mechanism that is adapted for use inXerographic reproducing machines or comparable types of devices.

One type of conveyer mechanism employed in Xerographic reproducingapparatus for conveying sheet sup port material from a receiving stationinto transfer contact with a xerographic surface and then to deliverystation is disclosed in Pat. No. 3,071,370 issued Jan. 1, 1963 to RobertA. Hunt and Gordon P. Taillie.

In this type of conveyer a gripper mechanism is used to transport asheet material through a predetermined path. Positive action of thegripper mechanism and accurate alignment of a chain drive carrying thegripper mechanism are necessary to insure proper alignment of sheetmaterial with a developed powder image on a Xerographic drum as thesheet is moved through the path of travel. Further, the sheet should betransported in a position parallel to the direction of movement thereofin order to provide proper registration and effective contact with theXerographic drum. The gripper mechanism is transported to thexerographic drum where the sheet material is moved into contact with thedrum by a lifting mechanism.

The gripper mechanism is actuated to a closed position at the receivingstation to positively grip the sheet material. The gripper mechanism isthen conveyed to a xerographic plate in the form of a drum where thesheet is moved into contact therewith by a paper lifting mechanism. Theforward movement of the gripper actuates the lifting mechanism as thesame moves past the xerographic drum. The gripper is then conveyed tothe releasing station where the gripper is opened and the sheet materialreleased. The sheet should be conveyed in a path substantially inparallel with the path of movement of the conveyer to prevent anyflutter thereof and to assist the lifting mechanism in maintaining thesheet material in contact with the Xerographic drum.

Therefore, it is an object of this invention to improve sheet grippingmechanisms.

A further object of this invention is to improve sheet grippingmechanisms to transport sheet material in a direction parallel to thedirection on movement thereof.

Yet another object of this invention is to improve sheet conveyingsystems.

Yet another object of this invention is to eliminate gripping marks, andlead edge crimping.

Another object of this invention is to simplify the opening and closingof sheet grippers.

3,531,109 Patented Sept. 29, 1970 A still further object is to improvestacking capabilities by keeping the sheet material flat.

These and other objects of the invention are attained by a sheetconveying system for carrying sheet material from a delivery station toa discharge station having a rod rotatably mounted for engagement withspring stock wherein the sheet material is secured between the rod andsheet material for positive gripping.

For a better understanding of the invention as well as other objects andfurther features thereof, reference is had to the following detaileddescription of the invention to be read in connection with theaccompanying drawings, wherein:

FIG. 1 illustrates schematically a preferred embodiment of the inventionin a xerographic apparatus;

FIG. 2 is a top view of the paper gripper mechanism shown with thegripper in open position;

FIG. 3 is a front view of the paper gripper mechanism shown in FIG. 2with the gripper in an open position;

FIG. 4 is an enlarged section view of the gripper mechanism taken alongline 4-4 of FIG. 2;

FIG. 5 is a section view taken along line 55 of FIG. 1;

FIG. 6 is atop view of the paper lift mechanism.

Referring now to FIG. 1, there is shown a continuous Xerographicreproduction machine containing the preferred embodiment of the presentinvention. The machine is of the type disclosed in the above-mentionedpatent to Hunt et al. The Xerographic apparatus comprises a xerographicdrum 20 which rotates in the direction indicated by the arrow to causethe drum surface sequentially to pass a plurality of xero graphicprocessing stations.

For the purpose of the present disclosure, several xerographicprocessing stations in the path of movement on the surface may bedescribed functionally, as follows:

A charging station at which a uniform electrostatic charge is depositedon the photoconductive layer of the Xerographic drum is shown at A. Anexposure station at which an image is projected onto the drum surfaceand a light to dissipate the drum charge on the exposed areas thereof,and thereby form a latent electrostatic image on the copy to bereproduced is shown at B. A developing station, where a xerographic drumis developed is shown at C. A transfer station at which the xerographicpowder image is electrostatically transferred from the drum surface tothe material is shown at D. A drum cleaning and discharge station isshown at E.

In the embodiment shown in FIGS. 1 and 2, the sheet feeding mechanismincludes a chain conveyer 26 which moves in a direction 28 carrying oneor more paper gripper mechanisms 30 in a circuit between sheet feedingstation 32 and a sheet delivery station 34. Means are provided toactivate the grippers to cause the grippers to take hold of the frontedge of a sheet of support material 36 inserted into the machine at thestation 32 and to hold the sheet while traveling to the delivery stationand to release the sheet for removal from the machine. In the embodimentshown, a sheet of transfer material is fed manually by an operator tothe paper gripper 30 and is forwarded by the paper gripper into contactwith the xerographic drum 20 at image transfer station D.

As the paper gripper is advanced by the chain conveyor, it strips thetransfer material from the drum and transports it to a fixing device,such as a heat fuser 38 where the Xerographic powder images previouslytransferred to the support surface are permanently fixed thereto.

Operation of a paper conveyor is effected by actuation of a limit switch1LS, upon insertion of the sheet transfer material 36 into the papergripper at the sheet feeding station 32.

Referring in particular to FIGS. 2, 3, 4 and 5 the conveyor includes apair of endless roller chains 26, one on each side of the machine, whichpasses from sprocket 62 carried by axle 64 over sprockets 66 and 68carried by axles 70 and 72, respectively. The axle 70 has a paper liftmechanism mounted thereon to be described below. Sprockets 66 and 68guide the chain in a path tangential to the surface of the drum. Thechain is then carried over and around a second sprocket 74 on axle 76down to sprocket 78 secured to drive shaft 55 and then back to thesprocket 62 and axle 64.

Therefore, it is understood that each set of sprockets are positioned ontheir respective shafts or axles to space the chains apart from eachother by a distance greater than the length of the drum. The chains 26carry two paper grippers 30 which are spaced equally from each otheralong the length of the chain. The paper grippers are positioned on thechain at right angles to the path of travel of the chain for movementtherewith and in a circuit between the sheet feeding and sheet deliverystations.

After fusing, the finished copy is discharged from the apparatus at thesheet delivery station 34.

The paper gripper 30 includes side frame members 80 which are secured tothe chain conveyor 26.

A rear frame member 82 connects the side frame members 80 and is mountedtherebetween. Attached to the rear frame member 82 and extending alongthe top of the paper gripper 30 is a longitudinal strip of spring stock84 formed with cut out portions 86 along the front portion thereof.Extending to the front portion of the side frame members 80 is the body88 in the form of a piece of rigid material. Mounted for rotation withinthe body 88 is a rod 90 which can be moved in an arc of approximately 90are camming elements 92 attached to either end of rod 90. The rod 90 isformed with an opening 94 therein as shown in FIGS. 2 and 3.

The body 88 is formed with openings 89 therein. The cut out portions 86of the openings stock 84 are positioned above these openings 89. A paperlead edge control guide 91 is mounted within each opening 89 and issecured by a pin 93 which fits into an opening 95 in the guide 91 and anopening 97 in the body 88-. A leaf spring 99 is positioned between therear portion of the body 88 and the rear portion of the spring stock 84to maintain the lead edge guide in contact with the rod 90.

A sheet material may thus be inserted at the sheet delivery station 32and placed within the slot 94 of the rod 90. As the sheet material isinserted through the guides at the delivery station 32 the limit switch1-LS is actuated through an appropriate circuit, not shown, whichincludes a several second time delay. The sheet material is insertedinto the slot 94 and after the appropriate time lapse, the solenoidSOL-1 is actuated and serves to move the lever 96 in the direction bythe arrow as shown in FIG. 1. The lever 96 thus moves the cam actuator102 which is moved pivotally about a shaft 104. The cam actuator 102moves the cam 92 in a clockwise direction as shown in FIG. 1 thus movingthe rod 90 in a clockwise direction as shown in FIG. 4 to positivelygrip the sheet material between the upper surface 106 of the rod 90 andthe under surface of the extending portions 108 of the longitudinalspring stock 84. The lead edge of the support material a paper is guidedby the guide 91 and moved into a position to be gripped by the edge 107of the opening 94 in the rod 90. The machine is then operable in thenormal manner through the suitable circuit to move the gripper bar fromthe sheet delivery station 32 by means of the chain conveyor 26 to thesheet transfer station D.

As the gripper 30 is moved by the chain conveyor 26 and approaches thedrum 20, the paper lift mechanism 110 support on the idler shaft 111 isactuated. The leading edge of the gripper 30 contacts the lever 112which pivots about the pin 114 and moves the lever forward. The arms 116and 118 are moved downward by the lever 112 and rotate the paper liftsupport 120 counterclockwise. The support 120 is pivotally mounted onthe brackets 121 which are secured to the shaft 111. Thus, as thegripper 30 passes the paper lift mechanism 110 the paper lift support120 is moved below the path of movement of the gripper. After thegripper 30 passes the paper lift mechanism and releases the lever 112the paper lift support is returned to its normal position as shown inFIG. 1 by a pair of return springs 112 secured to the brackets 121 shownin FIG. 7. The support 120 returns to its normal position in a rapidmanner aided by the spring 122 to lift the support material carried bythe gripper into intimate contact with the drum 20 to eliminate any leadedge deletion and maintain contact between the support material and thedrum. The gripper is then transported to the delivery station. Toaccomplish the discharge of the sheet material there is provided a pairof delivery rollers and 142. Delivery roll 140 is an idler rolljournaled for rotation in the frame 141 of the xerographic machine.Delivery roll 142 is driven by a sprocket 144 driven by the chainconveyor 26. The sprocket 144 drives a gear 146 through the shaft 148 towhich the gear 146 is keyed. The gear 146 in turn drives the drivendelivery roller 142, which is keyed to gear 197. The idler delivery roll140 has an O-ring 150 mounted thereon and serves to drive the idlerdelivery roll 140 when in contact with the driven delivery roll 142. Thedriven roll assembly is moved out of contact with the idler deliveryroll 40 by means of a SOL-2 as shown in FIG. 1 which is attached to theassembly by the arm 152 of the solenoid SOL-2. The solenoid SOL2actuated through a suitable circuit by a limit switch mounted adjacentthe conveyor and actuated by the conveyor 26 at the appropriate time asthe paper gripper mechanism approaches the delivery rolls. As thegripper approaches the rear feed out rolls SOL-2 is actuated therebymoving the rear feed out assembly of position to allow the gripper topass the delivery rolls. After the gripper mechanism has passed thedelivery rolls, solenoid SOL-2 is released allowing the driven deliveryI011 142 to engage the sheet material and drive the roller 140 tocontinuously feed the remaining portion of the sheet material from themachine. As the gripper passes the rear feed-out rolls 140-142 thesupport material is released from the paper by a camming mechanism whichmoves the rod 90 to the open position. The driven delivery roll 142 thencontinues to feed material from the machine into an appropriatecollecting tray (not shown). The gripper bar will return to the feedingstation 28 wherein the cycle can be repeated.

Although the sheet conveyor mechanism and the gripper bar actuatingmechanism has been described with reference to the structure of apreferred embodiment disclosed herein, it is not confined to the detailsset forth.

What is claimed is:

1. A gripping device for transporting copy sheet material including agripper housing,

said gripper housing having mounted thereon and extending along thelength thereof spring stock,

a rod mounted for rotation on said housing in sliding contact with saidspring stock,

said rod having a slot therein for receiving copy sheet material,

actuating means connected to said rod to cause said rod to rotate topositively grip said sheet material moved into said slot between saidrod and said spring stock without crimping or otherwise marring the leadedge thereof.

2. A gripping device for transportation of sheet material including agripper housing,

said gripper housing having mounted thereon and extending along thelength thereof spring stock,

a rod mounted for rotation on said housing,

said rod having a slot therein for receiving sheet material,

actuating means connected to said rod to cause said sheet material to beheld between said rod and said spring stock,

wherein said spring stock is formed with openings in the front portionthereof, 10

at least one lead edge guide mounted within the housing and extendinginto any one of said openings formed in said spring stock to guide theleading edge of the sheet material.

3. A device as recited in claim 2 wherein each lead 1 edge guide isarcuate in shape and is movably mounted to engage the rotatable rod.

4. A device as recited in claim 3 wherein each lead edge guide is biasedagainst the rotatable rod for positive engagement therewith.

References Cited FOREIGN PATENTS 870,061 3/1953 Germany.

RICHARD E. AEGERTER, Primary Examiner U.S. Cl. X.R. 198179

